Recently fixed very nasty defect crackle both channels of Sansui AU 3900 amp. The cause is pair transistors TR601 and TR602 of microphone amplifier! Their Crackle was going to the power supply effecting to all circuit.

Item: Sennheiser PXC450 Noise Cancelling headphones
Location: Melbourne
Price: 160
Item Condition: mint
Reason for selling: do not use
Payment Method: Pickup - Cash, Paypal, COD Only
Extra Info:
Sennheiser PXC450 Noise Cancelling headphones w/ Case, factory pack/box, manual etc. Mint condition. They were used just for some occasions.
These Sennheiser PXC 450 headphones are great for blocking out noise whilst giving superior sound quality. It has a switch to turn it to normal headphones to save battery. One of the best noise cancelling headphones money can buy.
Ear pads were replace with new one and phones were disinfected for hygiene propose.
https://au.pcmag.com/headphones/7943/sennheiser-pxc-450-noisegard
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